Colorado singer and guitarist Grayson Erhard has included a cover of Stevie Wonder’s 1972 hit “Superstition” in his live shows for several years. But the Del Norte native never learned all the lyrics to the song: he plays an abbreviated version that leaves out the second and third verses.

When he performed the song at a music convention in Anaheim, Calif., this year, he got the surprise of his life: Wonder was in the audience.

That led to a somewhat awkward moment for Erhard when he admitted he didn’t know all the lyrics to "Superstition" after finishing the song. Wonder then decided to join him onstage and trade off vocals with Erhard as the audience cheered in amazement. Watch that performance above.

"It changed my life," Erhard says of the experience. "It changed my entire outlook on being an artist."

Erhard -- a former member of Fort Collins folk band Pandas & People -- recently released the single "Cave." It's an instrumental acoustic song but he tells Colorado Matters host Nathan Heffel that his own material fits well next to "Superstition" during his live shows.

Listen to Grayson Erhard's recent performance for CPR's OpenAir.